1. Field
The present invention relates to a power conversion system for electric systems, and more particularly, to a power conversion system for electric vehicles.
2. Description of the Related Art
A power conversion system, which may be used in electric vehicles, may be capable of performing a retrogression operation (e.g., a downgrade operation or the operation of going from a better/higher state to a worse/lesser state) of boosting a DC voltage of a DC main power supply (e.g., DC voltage of a 48V battery) using a single boosting circuit, converting the DC voltage into an AC voltage using an inverter circuit, and outputting the AC voltage to a motor/generator. The power conversion system may also be capable of performing a regeneration operation of supplying regeneration power of the motor/generator to the DC main power supply, peripheral equipment (e.g., an electric power steering, an air conditioner, an engine control unit (ECU), and the like) of an electric vehicle, and an DC auxiliary power supply (e.g., an auxiliary 12V/24V battery) via the inverter circuit and the boosting circuit.
When using the power conversion system in the electric vehicles, there may not be a need for an alternator, which supplies power to the DC power supply, the peripheral devices of an electric vehicle, and the DC auxiliary power supply. However, when a single boosting circuit stops due to a defect, an electric circuit for recovering power to the DC main power supply or the DC auxiliary power supply is faulty (e.g., broken or malfunctioning) and therefore the regeneration operation from the motor/generator may not be performed. Accordingly, the electric vehicle may not be driven in the state in which the power of the DC auxiliary power supply is depleted.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is known to a person of ordinary skill in the art.